Propeller



July 27, 1931' w, WEBER 2,088,112

PROPELLER Filed Sept. 21; 1936 I 2 Sheets-Sheet 1 F1 1 4 5a'51z5c 5055 51 III 24 will/11 5a ma i 5 5T INVENTOR. 14 1 l 11 am H Leuzweber HIS ATTORNEY.

July 27, 1937. w. H. LEINWEBER PROPELLER Filed Sept. 21, 1936 2 Sheets-Sheet 2 //,,IIIII I [NVENTOR Mllwm/ H Leznweber aze/Wei HIS ATTO Patented July 27,1931

UNITED STATES PATENT OFFICE 12 Claims.

This invention relates to propellers, and has for a principal object the provision of an improved propeller of greater working efliciency which may readily be cast or otherwise formed from a vari ety of materials.

Another and more specific object is the provision of a propeller adapted to work in a fluid ymedium such as water, or air, and to lead fluid in adjacent the hub' portion thereof, and expel such fluid either at the blade tips'or at points adjacent the tips, depending upon the nature of the fluid. I

An object of the invention is, in, addition to j those recited above, the provision of a propeller having blades with the leading edges positioned axially in advance of the hub, and having their working surfaces curved in at least two directions substantially at right angles to one another.

2 stood with reference to the annexed drawings, in

which: I

Fig. 1 is a top plan view of a propeller adapted for use with water; 1 Fig. 2 is a side elevation of this propeller; Fig. 3 is a perspective view of the same;

- Fig. 4 is a section taken along lines 4-4 of Fig. 1';

Fig. 5 is a-group of related sections including Figs. 5a to 5 as sections taken-along the correspondingly lettered lines of Fig. 1;

Fig. 6 is a top plan view of an air type propeller;

Fig. 7 is a side elevation of the same; Fig. 8 is a perspective view;

Fig. 9 is a section along the lines 99 of Fig. ,6;

and

Fig. 10 is a group of related sections including Figs. 10' to 102 as sections taken along the correspondingly lettered lines of Fig. 6.

The improved propeller comprises a'hub [2 (Fig. 1) provided with a bore l4, and a pair of diametrically opposed blades 18 which are otherwise identical. I

As seen in Fig. 1, these blades are somewhat heart-shaped and extend from a juncture 20 with a hub l2, along a major axis radiall of the hub,

to terminate in a curved tip 22.

Each of the blades has a curved leading edge 24 which, as appears most readily from Fig. 2, are extended axially in advance of the upper extremity of the hub 12, these edge portions being curved in conformity with the sectional view of Fig. 5a, the object in so forming the leading edges being to draw the air or water inwardly from the region immediately surrounding the hub, for the The invention will be most conveniently underblade structure, is the double curvature given the working surfaces of the blades. If the major axis 5 of a blade is considered as a line drawn from the center of the hub toward the tip 22, and the minor axis is taken from points adjacent the tip 22 and the leading edge 24, and thus at an angle to the major axis (for instance, the radius RR 10 and the section line 4-4 of Fig. 1 being the major and minor axes respectively, and the corresponding curvatures being indicated by the dotted tracer arrows A and B in Fig. 2), the curvatures of the blades maybe said to be concave 15 along the minor axis.(viewed from the frontofthe propeller), and convex in the direction of the major axis.

This latter description applies particularly to the forward face of the right-hand blade seen in 20 Figs. 1 and 2, and obviously the undermost or inner and pressure surface seen in the left-hand bladeoi Fig. 2 will have its curvature reversed relative tojthe forward surface.

The undermost or working surface of each of 2 5 the blades of Fig. 2, is curved in accordance with 'the indications of the tracer'arrows A and B! so as to provide the convex curvature A extending generally between the tip 22 and leading edge 24 of the left-hand blade, and a generally 30 concave curvature B extending from the hub toward the tip 22.

- This curved conformation .,of the blades is generally peculiar to both the type shown inFig.

l and in Fig. 6, the diiference between these two 35 forms lying in their adaptability for use with water, in the instance of the type shown in Fig. 1, and with air in the case of the type shown in Fig. 6. However, since it is desirable, where the propeller is to be worked in water, to thrust the 40 water away from the blade in the general direction of the tips 22, the curvature along the socalled minor axis, that is, from the region of the leading edge 24 to the region of the tip 22, is'accentuated in the direction of the tip so as to cause 45 the water to be finallyythrust "away from the blade in the region of the tip, whereas in the case of air, the curvature along the so-called minor axis is convex (viewed from the front of the propeller) instead of, concave, with the result that the air 50' is thrust away from the-rear or trailing edge26' at points between the tip and the hub.

Inthe air typeof blade shown in Figs. 6 and '7 particularly, the convex curvature is indicated by the dotted tracer arrows 'c and n onthe modified 55 blade l8, it being observed that the curvature represented by the tracer C extends generally along a line beginning from the juncture 20' of blade I8, withthe hub I2, and extending in a somewhat radial direction outwardly toward the entering edge of the blade between the leading edge 24' and the tip 22', while the convexity of this same blade in the opposite direction; as indicated by the tracer D, begins at a point in the region of the leading edge 24' and curves rearwardly toward the trailing edge 26 and, as indicated, at an angle to the line of curvature of tracer C. Evidently, the curvature on the underside or working surface of the blade will be opposite to that just described in conjunction with the forward surface of the right-hand blade seen in Figs. 6 and '7, this curvature being concave along two axes running at an angleto one another as indicated particularly by the tracer arrows C and D in Fig. '7.

Further illustrative of the differences in curvature provided in the water and air types of blade, as represented respectively by the blades shown in Figs. 1 and 6, are the perspective views of Figs. 3 and 8, in which it will be observed that a valley or channel, generally indicated at 30, is formed by the curvatures of the blade to lead from the hub substantially in the direction .of the so-called major axis', radially toward the tip 24, while in Fig. 8 the channel or valley generally indicated at 32, leads from the hub l2 in the general direction of the rear or trailing edge 26.

In the operation of the type of blade shown in Fig. 1, for example, water will be drawn in, in

' the region of the hub I2, as the propeller is roleading edge 24 toward'the tip and which corresponds to the line of curvature A of Fig. 2 ortracer arrow 30 of Fig. 3. I

The operation of the air type of blade, shown in Fig. 6, 'is substantially the same and is such' that when the propeller is rotated in an anti-clockwise direction, as seen in this figure, air will enter from a point adjacent the leading edge 24' andfol- .low a channel or valley corresponding generally to the' dotted line D of Fig. '7, or the tracer arrow 32 of Fig. 8, to leave at the rear or trailing edge 26..

It will be observed that my improved propeller provides blades having a double or compound curvature in two directions and substantially at an angle each to the other, together with leading edge portions which in part, by virtue-pf, such curvature, are positioned in advance of the propeller hub and which are .adapted to draw or grab the working fluid in the immediate region surrounding the hub, and by further virtue of.

While 1 have described the embodiment shown herein in specific terms, it will be understood that I do not intend to be limited by such recitations except as'may be hereinafter provided in the annexed claims, which I desire to protect by Letters Patent of the United States.

I claim:

1. A propeller comprising a hub having a plurality of blades extended therefrom, the said blades having a leading edge positioned axially in advance of said hub, and a tip edge in the region of the radial extremities of the blades, the said blades being curved on their pressure faces along an axis extended between their said leading and tip edges and also along an axis extended substantially from the region of the hub toward said tip edge.

2. A propeller comprising a hub having a plurality of radially extended blades each provided with a leading edge positioned axially in advance of an end of said hub and a tip edge adjacent the radial extremity of the blade, and having a double superficial curvature along axes directed angularly with respect to one another in the pressure face of each said blade and extending respectively from said leading to tip edges and from said hub to said tip' edge.

3. A propeller including a hub and blades extended radially therefrom, each said blade having a leading edge positioned axially in advance of said hub, and a tip edge at their radial extremities, the working surfaces of said blades having a convex curvature extended 'between the said leading and tip edges and a concave curvature extending substantially between the said tip edges and the said hub.

4. A propeller comprising a hub portion with blades extended radially therefrom, each said blade having a leading edge positioned axially in advance of the hub, and a tip corresponding to the radial extremities of the'blades, the driving surface of each said blade being curved concavely in the region generally lying between the said leading edges and tips and also in the region lying between the said hub and a point along the forward edge of the blade intermediate of said leading edge and tip.

5. A propeller comprising a hub and blades extended therefrom, each said blade having a part extended in advance of the hub in an axial direction, and having a concavo-convex curvature substantially throughout the superficial extent of its working surface.

6. A propellercomprising a hub having blades extended radially therefrom, each said blade having a part extended in advance of the hub in an axial direction and being curved convexly in the region intervening between said extended part and the radial extremities of the blade, and the latter being concavely curved from a point adjacent its juncture with said hub in a direction radially outward therefrom to the edge of the blade lying between said extended part and the said radial extremity of the blade, both said curvatures characterizing the pressure surface of the blade.

7. A propeller including a hub having radially disposedblades each provided with a. leading edge part extended axially beyond said hub and having a convex working surfaceportion lying between the radial extremity of the blade and said leading edge part, said blades further having a. concavely curved working surface portion in the region between the juncture of the hub and blade and the region between said leading edge part andthe radial extremity of the blade.

8. A propeller including a hub having radially extended blades each provided with a leading edge part which projects in an axial direction beyond an extremity of the hub, each said blade having two surface curvatures on its working face, one said curvature lying in the region along the juncture of the blade with the hub toward the edge of the blade lying between the said leading edge part and the radial extremity of the blade.

9. A propeller including a hub and blades extended radially therefrom, each said blade having a part extendedaxially in advance of an end of the hub and having a concave-convex pressure surface curvature.

10. A propeller including a hub and blades extended radially therefrom, each said blade hav ing a part projecting axially in advance of an end of said hub and having a working surface with a, convex curvature in two directions along axes at an angle to each other.

11. A propeller including a hub having radially extended blades each provided with a leading edge part which projects in an axial direction beyond an extremity of the hub, each said blade having two surface curvatures on its working face, one said curvature lying in the region along an axis extended between the radial extremity of the blade and the leading edge part thereof, and the other said surface curvature lying substantlally along an axis extended in a direction from the juncture of the blade with the hub toward the edge of the blade lying between the said leading edge part and the radial extremity of the blade, the radii of curvature of each of said two surface curvatures being directed from the same side of the blade.

12. A propeller including a hub and blades extended radially therefrom, each said blade having a leading part extended axially in advance of an end of the hub and each having a concaveconvex working surface curvature with its respecti'ye radii of curvature extended from opposite sides of the blade.

WILLIAM H. LEINW aB" ER. 

